Gov. Jerry Brown has signed legislation limiting full-contact football practice for California teenagers, his office announced Monday.

The legislation comes amid increasing concern about brain injuries in football. Assembly Bill 2127, by Assemblyman Ken Cooley, D-Rancho Cordova, prohibits middle school and high school football teams from holding full-contact practices during the off-season and limits them to no more than two full-contact practices per week during the preseason and regular season.

Nineteen other states have banned full-contact high school football practices in the off-season, according to a legislative analysis.

Brown signed the bill without comment, one of 23 measures the Democratic governor announced signing Monday. Among other bills, Brown signed legislation allowing underage winemaking students to taste alcohol.

Assembly Bill 1989, by Assemblyman Wesley Chesbro, D-Arcata, creates an exemption to California's prohibition on furnishing alcohol to minors, allowing 18-, 19- and 20-year-old students in enology and brewing science to taste alcohol as part of their classes.